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<b>DB_MPOOLFILE-&gt;set_priority</b>
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<b><pre>
#include &lt;db.h&gt;
<p>
int
DB_MPOOLFILE-&gt;set_priority(DB_MPOOLFILE *mpf, DB_CACHE_PRIORITY priority);
<p>
int
DB_MPOOLFILE-&gt;get_priority(DB_MPOOLFILE *mpf, DB_CACHE_PRIORITY *priorityp);
</pre></b>
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<b>Description: DB_MPOOLFILE-&gt;set_priority</b>
<!--$Id: dbc_set_priority.so,v 1.3 2007/05/22 18:06:05 bostic Exp $-->
<p>Set the cache priority for pages referenced by the
<a href="../api_c/mempfile_class.html">DB_MPOOLFILE</a>
handle.</p>
<p>The priority of a page biases the replacement algorithm to be more or
less likely to discard a page when space is needed in the buffer pool.
The bias is temporary, and pages will eventually be discarded if they
are not referenced again.  The DB_MPOOLFILE-&gt;set_priority method is only advisory, and does
not guarantee pages will be treated in a specific way.</p>
<p>To set the priority for the pages belonging to a particular database,
call the DB_MPOOLFILE-&gt;set_priority method using the <a href="../api_c/mempfile_class.html">DB_MPOOLFILE</a> handle
returned by the <a href="../api_c/db_get_mpf.html">DB-&gt;get_mpf</a> method.</p>
<p>The DB_MPOOLFILE-&gt;set_priority method configures a file in the memory pool, not only
operations performed using the specified <a href="../api_c/mempfile_class.html">DB_MPOOLFILE</a> handle.</p>
<p>The DB_MPOOLFILE-&gt;set_priority method may be called at any time during the life of the
application.</p>
<p>The DB_MPOOLFILE-&gt;set_priority method
returns a non-zero error value on failure
and 0 on success.
</p>
<b>Parameters</b> <br>
 <b>priority</b><ul compact><li>The <b>priority</b> parameter must be set to one of the following
values:
<br>
<b><a name="DB_PRIORITY_VERY_LOW">DB_PRIORITY_VERY_LOW</a></b><ul compact><li>The lowest priority: pages are the most likely to be discarded.</ul>
<b><a name="DB_PRIORITY_LOW">DB_PRIORITY_LOW</a></b><ul compact><li>The next lowest priority.</ul>
<b><a name="DB_PRIORITY_DEFAULT">DB_PRIORITY_DEFAULT</a></b><ul compact><li>The default priority.</ul>
<b><a name="DB_PRIORITY_HIGH">DB_PRIORITY_HIGH</a></b><ul compact><li>The next highest priority.</ul>
<b><a name="DB_PRIORITY_VERY_HIGH">DB_PRIORITY_VERY_HIGH</a></b><ul compact><li>The highest priority: pages are the least likely to be discarded.</ul>
<br></ul>
<br>
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<b>Description: DB_MPOOLFILE-&gt;get_priority</b>
<p>The DB_MPOOLFILE-&gt;get_priority method returns the cache priority for the file referenced by the <a href="../api_c/mempfile_class.html">DB_MPOOLFILE</a> handle.</p>
<p>The DB_MPOOLFILE-&gt;get_priority method may be called at any time during the life of the
application.</p>
<p>The DB_MPOOLFILE-&gt;get_priority method
returns a non-zero error value on failure
and 0 on success.
</p>
<b>Parameters</b> <br>
 <b>priorityp</b><ul compact><li>The DB_MPOOLFILE-&gt;get_priority method returns a reference to the
cache priority for the file referenced by the <a href="../api_c/mempfile_class.html">DB_MPOOLFILE</a> handle in <b>priorityp</b>.</ul>
<br>
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<br><b>Class</b>
<a href="../api_c/env_class.html">DB_ENV</a>, <a href="../api_c/mempfile_class.html">DB_MPOOLFILE</a>
<br><b>See Also</b>
<a href="../api_c/memp_list.html">Memory Pools and Related Methods</a>
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